diff options
Diffstat (limited to 'src/hkdf.c')
| -rw-r--r-- | src/hkdf.c | 30 |
1 files changed, 13 insertions, 17 deletions
@@ -42,16 +42,15 @@ static _nc_fn_inline void debugValidateHandler(const struct nc_hkdf_fn_cb_struct cstatus_t hkdfExpandProcess( const struct nc_hkdf_fn_cb_struct* handler, void* ctx, - const cspan_t* info, - span_t* okm + cspan_t info, + span_t okm ) { cstatus_t result; - - uint8_t counter; + cspan_t tSpan, counterSpan; uint32_t tLen, okmOffset; + uint8_t counter[1]; uint8_t t[HKDF_IN_BUF_SIZE]; - cspan_t tSpan, counterSpan; debugValidateHandler(handler); @@ -59,18 +58,18 @@ cstatus_t hkdfExpandProcess( tLen = 0; /* T(0) is an empty string(zero length) */ okmOffset = 0; - counter = 1; /* counter is offset by 1 for init */ + counter[0] = 1; /* counter is offset by 1 for init */ result = CSTATUS_FAIL; /* Start in fail state */ /* counter as a span */ - ncSpanInitC(&counterSpan, &counter, sizeof(counter)); + ncSpanInitC(&counterSpan, counter, sizeof(counter)); /* Compute T(N) = HMAC(prk, T(n-1) | info | n) */ - while (okmOffset < okm->size) + while (okmOffset < okm.size) { ncSpanInitC(&tSpan, t, tLen); - if (handler->update(ctx, &tSpan) != CSTATUS_OK) + if (handler->update(ctx, tSpan) != CSTATUS_OK) { goto Exit; } @@ -80,7 +79,7 @@ cstatus_t hkdfExpandProcess( goto Exit; } - if (handler->update(ctx, &counterSpan) != CSTATUS_OK) + if (handler->update(ctx, counterSpan) != CSTATUS_OK) { goto Exit; } @@ -96,18 +95,15 @@ cstatus_t hkdfExpandProcess( } /* tlen becomes the hash size or remaining okm size */ - tLen = HKDF_MIN(okm->size - okmOffset, SHA256_DIGEST_SIZE); + tLen = HKDF_MIN(okm.size - okmOffset, SHA256_DIGEST_SIZE); DEBUG_ASSERT(tLen <= sizeof(t)); - /* write the T buffer back to okm */ - ncSpanWrite(*okm, okmOffset, t, tLen); - - /* shift base okm pointer by T */ - okmOffset += tLen; + /* write the T buffer back to okm and advance okmOffset by tLen */ + ncSpanAppend(okm, &okmOffset, t, tLen); /* increment counter */ - counter++; + (*counter)++; } result = CSTATUS_OK; /* HMAC operation completed, so set success */ |